Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size, wherein the step size of a step-up is equal to or smaller than the step size of a step-down and wherein the control unit is further configured to switch, upon reaching or exceeding a predefined threshold value, from a first to a second state having a smaller step size and causing the attenuator to change the gain such that the slope of the RF signal inverts and to switch, upon reachi

Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size, wherein the step size of a step-up is equal to or smaller than the step size of a step-down and wherein the control unit is further configured to switch, upon reaching or exceeding a predefined threshold value, from a first to a second state having a smaller step size and causing the attenuator to change the gain such that the slope of the RF signal inverts and to switch, upon reachi

Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size.

Abstract: An electronic device which includes a first stage having an input capacitance, a switch, a buffer and a second stage having an input sensitive to charge injection and/or voltage glitches. An input of the buffer and the input of the second stage are coupled together at a first node which is configured to be coupled to a voltage source for supplying a reference voltage to the input of the first stage having the input capacitance. In a first configuration of the switch, the switch is arranged to either connect the input of the first stage to the first node and to disconnect the input of the first stage from an output of the buffer. In a second configuration of the switch, to connect the input of the first stage to the output of the buffer and to disconnect the input of the first stage from the first node.

Abstract: An electronic device, including a first limiter including a first transistor configured to be coupled with a first side of a channel to a first output node of a non-ideal voltage source having an inner impedance greater zero in order to limit the voltage at the first output node by drawing a current from the first output node. The second side of the channel of the first transistor is coupled to a capacitor so as to supply a current from the first output node to the capacitor, if the voltage level at the output node reaches or exceeds an upper limit.

Abstract: An electronic device is provided that is adapted to generate a supply voltage at an input node from a radio frequency (RF) signal. The electronic device includes a limiter coupled to the input node for limiting a supply voltage level at the input node that is generated by the received RF signal. The limiter is configured to draw a limiter current from the input node so as to limit the supply voltage level to a maximum and a magnitude of the limiter current is used for controlling a power consumption of the electronic device.

Abstract: An electronic device comprising an amplifier having at least a first input transistor of a first doping type. A first transistor is coupled with a channel as a feedback path between an output of the amplifier and a control gate of the first input transistor forming an input of the amplifier. A diode-coupled second transistor is coupled with a channel between a first current source and the output of the amplifier wherein a control gate of the first transistor is coupled between the first current source and the diode-coupled second transistor and the first transistor is of a second doping type which is opposite to the first doping type of the first input transistor of the amplifier.

Abstract: An electronic device comprising an amplifier having at least a first input transistor of a first doping type. A first transistor is coupled with a channel as a feedback path between an output of the amplifier and a control gate of the first input transistor forming an input of the amplifier. A diode-coupled second transistor is coupled with a channel between a first current source and the output of the amplifier wherein a control gate of the first transistor is coupled between the first current source and the diode-coupled second transistor and the first transistor is of a second doping type which is opposite to the first doping type of the first input transistor of the amplifier.

Abstract: An electronic device, including a first limiter including a first transistor configured to be coupled with a first side of a channel to a first output node of a non-ideal voltage source having an inner impedance greater zero in order to limit the voltage at the first output node by drawing a current from the first output node. The second side of the channel of the first transistor is coupled to a capacitor so as to supply a current from the first output node to the capacitor, if the voltage level at the output node reaches or exceeds an upper limit.

Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size.

Abstract: An electronic device which includes a first stage having an input capacitance, a switch, a buffer and a second stage having an input sensitive to charge injection and/or voltage glitches. An input of the buffer and the input of the second stage are coupled together at a first node which is configured to be coupled to a voltage source for supplying a reference voltage to the input of the first stage having the input capacitance. In a first configuration of the switch, the switch is arranged to either connect the input of the first stage to the first node and to disconnect the input of the first stage from an output of the buffer. In a second configuration of the switch, to connect the input of the first stage to the output of the buffer and to disconnect the input of the first stage from the first node.

Abstract: An ASK demodulator for use in an RFID transponder having a limiter circuit associated with the antenna circuit and converting the ASK antenna field strength modulation into an ASK limiter current modulation by limiting the antenna voltage to a fixed value and thereby causing the limiter current to be substantially proportional to the ASK antenna field strength, and a current discriminator circuit that discriminates the ASK limiter current modulation. By converting the field strength modulation into a proportional limiter current and discriminating that limiter current, a linear relationship and a stable demodulator sensitivity are achieved. The current discrimination can be made accurately under low-voltage conditions.

Abstract: An electronic device is provided that is adapted to generate a supply voltage at an input node from a radio frequency (RF) signal. The electronic device includes a limiter coupled to the input node for limiting a supply voltage level at the input node that is generated by the received RF signal. The limiter is configured to draw a limiter current from the input node so as to limit the supply voltage level to a maximum and a magnitude of the limiter current is used for controlling a power consumption of the electronic device.

Abstract: An ASK demodulator for use in an RFID transponder having a limiter circuit associated with the antenna circuit and converting the ASK antenna fieldstrength modulation into an ASK limiter current modulation by limiting the antenna voltage to a fixed value and thereby causing the limiter current to be substantially proportional to the ASK antenna field strength, and a current discriminator circuit that discriminates the ASK limiter current modulation. By converting the fieldstrength modulation into a proportional limiter current and discriminating that limiter current, a linear relationship and a stable demodulator sensitivity are achieved. The current discrimination can be made accurately under low-voltage conditions.

Abstract: Methods and systems to achieve linear and exponential control over a current to drive color LEDs have been achieved. Current digital-to-analog converters (IDAC) comprising each an exponential current digital-to analog converter and a linear IDAC, being cascaded to each other are used for a linear and an exponential control of a current driving a set of color LEDs, preferably RGB LEDs. The linear part of the IDAC, which is converting the mantissa of a floating-point number is used to control the color composition of the color LEDs. The exponential part of the IDAC, which is converting the exponent of the floating-point number is used to control the brightness of the color LEDs. While fading from one color to a next color a linear color change is required. The exponential part of the IDAC is used to dim the LEDs from bright to dark and vice versa. In order to get the visual perception of a linear dimming an exponential current change is required.

Abstract: A high voltage digital output driver with dynamically biased cascode transistors is disclosed. The cascode transistors are dynamically self-biased via capacitors from the output voltage. The dynamic self-biasing doesn't require any switching means. The output-voltage can be increased by adding additional self-biased cascode transistors. The static current consumption in low-state for each individual driver on a same chip is minimal because only one resistor string consuming static current is required for all similar output drivers.

Abstract: A charge pump circuit with a regulated charge current where the amount of current flowing into the flying capacitor depends on the magnitude of the output voltage error, using an OTA to convert the output voltage error into a current. Thus the flying capacitor is not charged when the output load is very low or when the output voltage error is minimal. Voltage overshoots are reduced by a stop circuit which forces pulse skipping and which inhibits the charging of the flying capacitor. Current limiting devices further limit the charge current into the flying capacitor. Full short-circuit protection is provided in one preferred embodiment by current limiting the driver stage of the charge pump circuit. Except for pulse skipping, the charge pump runs at a constant frequency supplied by a clock.

Abstract: Circuits and methods to convert a digital floating-point number into an analog current have been achieved. The conversion is performed directly by using an exponential current digital-to-analog converter (DAC) and a cascaded linear current digital-to-analog converter (DAC). The exponential current DAC is converting exponentially the exponent of the floating-point number, its output current is biasing the linear DAC, which is converting the mantissa of the floating-point number. The output current of the linear current DAC is correlates linearly with the value of the floating-point number. This technique is commutative, this means the sequence of the linear and the exponential converter can be interchanged. In this case the linear converter provides a biasing current to the exponential converter. The sign bit can be considered by converting the direction of the output current of the converter. This floating-point number conversion can handle a very high dynamic range and requires a minimum of chip space.

Abstract: Methods and systems to achieve linear and exponential control over a current to drive color LEDs have been achieved. Current digital-to-analog converters (IDAC) comprising each an exponential current digital-to analog converter and a linear IDAC, being cascaded to each other are used for a linear and an exponential control of a current driving a set of color LEDs, preferably RGB LEDs. The linear part of the IDAC, which is converting the mantissa of a floating-point number is used to control the color composition of the color LEDs. The exponential part of the IDAC, which is converting the exponent of the floating-point number is used to control the brightness of the color LEDs. While fading from one color to a next color a linear color change is required. The exponential part of the IDAC is used to dim the LEDs from bright to dark and vice versa. In order to get the visual perception of a linear dimming an exponential current change is required.

Abstract: Methods and systems to achieve linear and exponential control over a current to drive color LEDs have been achieved. Current digital-to-analog converters (IDAC) comprising each an exponential current digital-to analog converter and a linear IDAC, being cascaded to each other are used for a linear and an exponential control of a current driving a set of color LEDs, preferably RGB LEDs. The linear part of the IDAC, which is converting the mantissa of a floating-point number is used to control the color composition of the color LEDs. The exponential part of the IDAC, which is converting the exponent of the floating-point number is used to control the brightness of the color LEDs. While fading from one color to a next color a linear color change is required. The exponential part of the IDAC is used to dim the LEDs from bright to dark and vice versa. In order to get the visual perception of a linear dimming an exponential current change is required.